As explained the other day I am working on a canvas cell renderer,
it has been working pretty well for some time now, except that the
contents of the canvas cells misteriously dissapeared when
scrolling through the table. I have no investigated the problem and
found the reason (and a solution).

The table.pane.Pane creates the content of the table pane by
joingin html fragments representing the individual rows of the
table and in the end inserting the result into the body of the
table.

The problem with the canvas element is that it can only have
rendered content while it is a DOM node, this means that if the
table pane recreates the table content by concatinating cached HTML
fragments and then reinserting them into the DOM, the content of
the rendered canvas cells will be lost.

short of rewriting the table widget I have found a workaround for
the problem. My cell renderer now contains a cache map storing the
canvas elements once they are rendered. Whenever the renderer is
triggered, it lookes up the elements in the cache and replaces the
freshly created canvas node with the already rendered aequivalent.

is the table widget realy faster by doing string manipulation
instead of jugging dom nodes ?

cheers
tobi

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch [email protected] ++41 62 775 9902 / sb: -9900

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